Overcoming resistance to BRAF(V600E) targeted therapies in melanoma

描述(由申请人提供)： 由于针对BRAF(V600E)突变的靶向治疗和免疫检查点阻断，晚期黑色素瘤的治疗正在经历一场革命。然而，无论是反应的大小和持久性都远远不是最佳的(PLX4032的中位数进展为~8个月)。该PPG采用系统、全面和跨学科的方法，通过药物和免疫治疗等组合方法来阐明和克服这种治疗耐药性。我们的团队由黑色素瘤生物学领域的领导者以及当前关键临床试验的主要研究人员组成。我们的方法建立在通过共享资源核心(核心A)利用体外培养技术和N0D/SCID/IL2RY-/-小鼠高效异种移植产生配对的、患者来源的敏感和耐药黑色素瘤样本和细胞系的基础上。这些标本和相应的患者将通过一套广泛的临床和分子标准进行注释，包括候选癌基因测序、基因组拷贝数和PLX4720 ICSO。同样配对的黑色素瘤样本随后将进行深度测序和全基因组测序。ShRNA表型筛选(项目1)，以确定与耐药性(合成致死性)相关的获得性突变和基因依赖性。确认/优先命中将建立在所有3个项目的集体知识的基础上。项目2将在基因定义的小鼠黑色素瘤模型中进行耐药机制和HIT验证的平行分析，包括测试项目1和项目3的候选对象，以及纳入对BRAF抑制剂具有获得性耐药性的肿瘤。在小鼠中确定的耐药性机制将被用来在人体研究(项目1)中确定候选人的优先顺序。项目3将研究在BRAF(V600E)抑制剂药物后对抗细胞凋亡的MITF途径-提供药物机会-还将研究免疫参与，这可能是MITF通过调节黑色素瘤抗原性来调节的。使用BRAF(V600E)拮抗剂和免疫检查点阻断的联合治疗将使用基因定义的小鼠进行仔细审查，并在患者中进行研究。由此产生的分子和功能数据集将通过博德研究所专门的生物信息学和生物统计学核心(核心B)进行整合，以确定每个平台的HIT的优先顺序和验证，告知耐药机制，提名敏感/耐药的生物标记物，并确定用于临床前/临床开发的可用药脆弱性。这些广泛整合的项目和核心的预测产出不能在单独的倡议中复制，但将在一个高度协作的多学科结构中发挥作用，以加速发现治愈方法。

DESCRIPTION (provided by applicant): Treatment of advanced melanoma is undergoing a revolution due to targeted therapeutics directed at BRAF(V600E) mutations and immune checkpoint blockade. However both the magnitude and durability of responses are very far from optimal (median progression on PLX4032 of ~8 months). This PPG takes a systematic, comprehensive, and interdisciplinary approach towards elucidating and overcoming this treatment resistance with combination approaches including drugs as well as immunotherapy. Our team consists of leaders in melanoma biology as well as principal investigators of key current clinical trials. Our approach builds on generating paired, patient-derived sensitive and resistant melanoma specimens and cell lines via a Shared Resource Core (Core A) using in vitro culture techniques and highly efficient xenografts in N0D/SCID/IL2RY-/- mice. These specimens, and corresponding patients, will be annotated by an extensive set of clinical and molecular criteria including candidate oncogene sequencing, genomic copy number, and PLX4720 ICSO. The same paired melanoma specimens will then undergo deep sequencing and full-genome. shRNA phenotypic screening (Project 1), to identify acquired mutations and gene dependencies associated with resistance (synthetic lethality). Validation/prioritization of hits will build on collective knowledge from ail 3 Projects. Project 2 will carry out parallel analyses of resistance mechanisms and hit validation in genetically defined mouse melanoma models, including the testing of candidates derived from Projects 1 & 3 and the incorporation of tumors with acquired resistance to BRAF inhibitors. Resistance mechanisms identified in mice will be utilized to prioritize among candidates among the human studies (Project 1). Project 3 will examine the MITF pathway which antagonizes apoptosis after BRAF(V600E) inhibitor drugs-offering drugable opportunities-and also study immune involvement which may be regulated by MITF via modulation of melanoma antigenicity. Combination therapy with BRAF(V600E) antagonists plus immune checkpoint blockade will be scrutinized using genetically defined mice and also studied in patients. The resulting molecular and functional datasets will be integrated via a specialized Bioinformatics and Biostatistics Core at the Broad Institute (Core B) to prioritize and validate hits from each platform, inform mechanisms of resistance, nominate biomarkers of sensitivity/resistance, and identify drug-able vulnerabilities for preclinical/clinical development. The predicted output of these extensively integrated Projects and Cores could not be replicated in separate initiatives, but will function within a highy collaborative, multi-disciplinary structure to accelerate the discovery of a cure.